Sister Wives star Maddie Brown Brush gave birth to a healthy baby boy — named Axel James Brush — PEOPLE can exclusively reveal.

Axel was born at 12:13 a.m. on Saturday, May 20, his exact due date. He clocked in at 8 lbs., 8 oz. and is 21-inches long.

The family’s little bundle of joy was born after 72 hours of labor — including 12 hours of hard labor and four hours of pushing.

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“We’re feeling both excited and exhausted at the same time,” the couple tells PEOPLE. “We’re looking forward to having a family. Now that he’s here we excited to grow our family a little bit more and spread our love even more.”

Maddie’s parents Kody and Janelle Brown are also excited about becoming first-time grandparents.

Raquel Werner Photography

“I think being grandparents hasn’t sunk in yet,” they tell PEOPLE. “It’s so fun. I can’t believe how much we love this baby already.”

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As for the rest of the Brown family — which includes four wives total and 18 children — Kody and Janelle admit that Axel has a large extended family that is waiting to meet him.

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“The whole family is excited. In fact the biggest trick will be giving Maddie her rest because there’s going to be this long line of parents and siblings that will be continuously wanting to hold the baby.”